The present invention relates to the field of fiber optics, and specifically to housings for optical components.
The increase in voice and data communications in recent years has contributed to a need to transmit and receive data at increasingly higher rates. Optical fiber communications systems are used to help meet this need. Advantages of optical fiber systems over, for example, electrical systems include increased bandwidth and smaller size. Packaging of fiber optic systems is an important factor to consider when attempting to achieve these smaller size systems.
Packaging optical components in a planar geometry (flat), rather than in a cylindrical geometry, is preferred to efficiently utilize space. FIG. 1 is a top view of a prior art planar package. Optical components such as isolators, taps, wavelength division multiplexers (WDMs), and lenses, are typically housed in area 2 (components not shown). Optical fiber pairs 4 and 6 are attached to collimated lens assemblies 10 and 12, respectively. Multiple collimated lens assemblies may also be attached to each of the two sides to which collimated lens assemblies 10 and 12 are attached (multiple collimated lens assemblies not shown in FIG. 1). Energy is optically coupled to components within area 2 through openings 14 in the housing 8.
Typically, collimated lens assemblies 10 and 12 are either laser welded or soldered to the housing 8. Laser welding often results in positional shifts of optical components after attachment. This shifting of components is referred to as post-weld shift. Post-weld shift often results in a misalignment of components. Misalignment can result in degraded processing performance, increased insertion loss, and, at times, discarding the assembly. Laser welding requires access, by the laser welder, to the surfaces to be welded. The spacing required between lens assemblies can inhibit the welding process. Spacing the lens assemblies far enough apart such that access is available to a laser welder limits the number of lens assemblies per side. Laser welding also requires high amounts of energy to perform the welding process.
Soldering requires sustained heat for relatively long periods of time in order to flow the solder. This heat often detrimentally affects other components. Another disadvantage associated with soldering is positional shifts of optical components caused by cooling shrinkage. This positional shift of components can cause the same detrimental effects as post-weld shift (e.g., component misalignment, increased insertion loss, and decreased processing performance). Thus, a need exists for a planar packaging apparatus and method which does not inherently suffer the above disadvantages.
A planar fiber optic housing comprises a region for retaining optical components in a planar configuration. At least one side of the region comprises an optically transmissive material for coupling optical components thereto.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention.